Brake-actuating mechanism



Sept. 15, 1925.

H. A. MENNE BRAKE ACTUATING MECHANISM Filed Aug. 4, 1924 2 Sheets-Shootl I inventor. flyfewna/n lmwww.

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BRAKE ACTUATING MECHANISM Filed Aug. 4, 1924 2 Sheets-Shut 2 PatentedSept. 15, 1925.

umrao "STATES PATENT ore-ice.

anauena. man, on sen rnaucrsco, cnmronm v Application filed August 4,1984. Serial No. 730,095.

To all whom it may concern:

Be it known that I, HERMAN A. MENNE, a citizen of the United States,residing at the city and county of San Francisco and State ofCalifornia, have invented new and useful Improvements in Brake-ActuatingMechanism, of which the following is a specification. I

This invention relates to vehicle brakes, and especially to a brakeactuating mechanism.

The object of the present invention is to generally improve and simplifythe construction and operation'of brake actuating mechanisms such as areemployed in conjunction with brakes using a brake drum, together with anexternal or internal expanding brake band, and particularly to provide abrake actuating mechanism which utilizes the gripping action between thebrake band and the drum to increase the braking action.

' One form which my invention may assume is exemplified in the followingdescription and illustrated in the accompanying drawings, in which- Fig.1 is a side elevation of a standard form of brake drum empgoying anexternal contracting form of bra e band, said view also disclosing thebrake band actuating mechanism forming the subject matter of the presentapplication.

Fig. 2 is a partial side elevation of the same mechanism illustrated inFig. 1, said view showing the brake band in gripping position.

Fig. 3 is also a side elevation of the drum and band, the major portionthereof being broken away, said view particularly illustrating theposition of the brake band actuating mechanism when fully applied.

Fig. 4 is a. plan view of the rear axle housing of an automobile,showing the position of the brake drum and the band, and the actuatingmechanism therefor.

Fig. 5 is a side elevation in section taken on line 5--5 of Fig. 4.

Referringto the drawings in detail, and

particularly to Figs. 1 and 4, A indicates the differential housing onan automobile, 2 the axle housing, 3 the hub of a standard form ofwheel, 4 the,brake drum secured thereto, and 5 an external brake bandsurrounding the same. The band is of the split type, as shown, and issupported with relation to the drum by means of brackets 6 and springleaf retainers 7, this feature be-. mg of no particular importance as itis more or less employed in standard practice. The spring leaves 7 are,however, a little longer 0 than usual to permit partial rotation of thebrake band with the drum, as will hereinafter be described.

The brake actuating mechanism forming the subject matter of the, presentinvention consists of a shaft 8, bne end of the shaft being journalledin a bearing bracket 9, as shown in Figs. 4 and 5, and the other endextending through a slot 10 formed in "a bracket 11. This bracket isriveted or otherwise secured, as indicated at 12, to the innerstationary-plate 13 of the brake drum housing, and it serves twofunctions, first, that of permitting vertical movement of the shaft 8 1nthe slot 10 and, secondly, that of supporting a pair of lugs generally,indicated at 14 and 15.

The outer end of the shaft which projects through the slotted bracket 11is provided with an arm 16, which .is keyed or otherwise securedthereto. One end of the arm is connected by means of a link 17 with oneend of the brake band, as indicated at 18, while the opposite end of thearm 16 is cop-' nected through a link 19 with 0. lug 20, which issecured to the opposite end of the brake band as indicated at 21. Theouter end of the link 19 is threaded to receive a nut 22 and this nut isemployed for the purpose of takin up wear between the brake band and therum in the usual manner. Also secured on the shaft 8, on the inner sideof the bracket 11, is an arm'23. This arm is clearly shown in full linesin Fig. 4 and in dotted lines in Figs. 1, 2 and 3. One end of the arm 23is adapted to en age the lug 14, while the opposite end is a apted toengage the lug 15. The object of permitting such an engagement will bemore fully described.

It will be noted by referring to Fig. 4 that only one wheel, togetherwith brake drum band and actuating mechanism, is shown. It should,however, be understood that the mechanism is'duplicated on each side andthat both brakes are actuated by an equalizing bar 24 throu h. means ofa rod 25 and foot pedal or the 'ke not shown.

It will also be'noted thatthe shaft 8 is cut off at the point indicatedat 8, In other words there are two shafts, one indicated at 8 and oneindicated at 8". The shaft 8 27. For the purpose of simplifying actuatesthe brake mechanism on the lefthand side, while theshaft 8 actuates thebrake mechanism on the right-hand side, which is not illustrated.

The inner ends of the shafts 8 and 8 are' provided with crank arms 26and 27 These crank arms are connected through links 28;

and 29 with the equalizing bar 24, and the shafts 8 and 8 may thus beturned in unison or-independently of each other as the case may be.- Theactual operation of the braking mechanism will be as follows:

When it is desired to-apply' the brakes, i

.is merely necessary to exert a pull on the rod 25 and the equalizingbar 24 throughmeans of a foot pedal or other actuating mechanism nothere disclosed. A pull thus imparted will impart a rotary movement tothe shaftsf'8 and8 through means of the links 28 and 29 and the crankarms 26 and the description, the turning movement 0 ence will be made-to Figs. 1, 2 and 3. a

The shaft 8, together withthe ai'ms 16 and 23 secured. thereto, normallyassumes the position shown inFigJ 1, but when shaft 8 is rotated in thedirection of arrow (1 (see Fig.

a downward pull is exerted on the linkdrum is rotating in the directionof arrow 6- (see Fig. 1). If this is the case, it will be seenthat thebrake 'band will have a tendency to rotate with the drum in the samedirection. Such rotating movement of the band with the drum is permittedto a limited extent. This will be understood when referonce is made toFig. 2, Fig. 2 showing the ositions of the arms 16 and 23 when the rakeband has been applied. The moment the band tends to rotate with thedrum, the

- outer end of the shaft 8 will move upwardly in the slot 10 and theinner. end of the arm 23, indicated at 23, will thus move upwardly intocontact with the lug 14. This lug limits the rotating movementof theband with the drum and thereby stops further rotating movement. The bandWlll, nevertheless, continue to exert an upward pull onthe' link 17 andthis pull will further tend to lift the shaft 8 upwardly in the slot 10.The arm 23 will, in other words, function as a lever with the lug 14 as'a-fulcrum point, and as this lever is'pulled upwardly apull will beexerted on the rod 19 and the lu 20, which is attached to the free end21 o the brake band. This pull tends to further ti hten the grippingaction between the ban and the rum and the braking action between thetwois increased. The engagement of the inner end 23 of the arm 23 with lug14 shaft 8 .alone will be described, and particular referis illustratedin Fig. 3, this view also show- I ing the upward movement-of the shaft 81n the slot 10. In other words, the gripping action produced between thebrake band and the drum is utilized to further increase the that thebrake more or less automatically,

applies itself once a contact is made between the brake band and thedrum.

The reason for employing two lugs is to when backing up. The mechanismacts the same whether the brake drum is rotating in one direction oranother, and it is for this reason that a double arm 23 is employed andsimilarly two lugs 14 and 15. v

The retainingspring leaves 7 are elongated, as shownin Figs. '1 and 2,for the purpose of permittin a limited rotating movement of the ban withthe drum, and theyotherwise serve the usual function, to-

wit, that of maintaining a clearance between .the brake band and thedrum/ when the ing mechanism is otherwise released-after application byreleasing the foot pedal or other actuating mechanism, and it is furtherreturned to normal position by a s ing such as indicated at 30,this'sprmg mg connected to a stationary bracket'31 at one end and totheequalizing bar 24' at the opposite Y end.

While certain features of the present in vention are more or lessspecifically illustrated, I wish it understood. that various changes inform and'proportion may be resorted to within the sco'pe of'theappended.

claims. I similarlylwish it understood that the materials and finish ofthe several parts employed may be such as the experience and judgment ofthe manufacturer may dictate or .various uses may demand.- v

Having thus described my invention,what. I- claim and desire to secureby Letters Pat ent isv 1. The combination with a rotatable brake drumand a brake band cooperatin there: with, of means permitting a rotary105 versal joints and the like. The brake actuatmovement of the bandwith the drum, a rocking floating member for imparting movement to theband to grip the drum, and means actuated by rotary movement of the bandwith the drum to transmit a further rocking movement to the floatingmember and thereby increase the gripping action of the band.

2. The combination with an axle, a brake drum and a split brake bandcooperating therewith, of asecond axle disposed in substantialparallelism with the first-named axle, an arm secured on said axle,links connecting the opposite ends of said arm with the op.- posite endsof the split brake band, means for imparting rotary movement to thesecond-named axle to apply the brake band, means permitting partialrotation of'the brake band with the drum when the brake hand is applied,means permitting movement of the second-named axle in unison with thebrake band, and means for trans mitting the rotary movement of the brakeband with the drum tothe second-named axle to further increase thegripping action ends of the second-named of said axle extending throughthe slotted bracket plate and having a floating movement in the slot, anarm secured on the axle, links connecting the opposite ends of said ,armwith the opposite ends of the split axle to further tighten the grlppingaction between the band and the drum.

4. The combination with the axle housing of an automobile, the brakedrum and a split brake band cooperating therewith, of a stationarybracket plate secured adjacent the drum, said bracket plate having aslot formed therein, an axle disposed in substantial parallelism withthe axle housing, one end of said axle extending through the slottedbracket plate and having a floating movement in the slot, an arm securedon the axle, links connecting the opposite ends of said arm with theopposite ends of the split brake band, means for imparting a. rotarymove ment to the axle to apply the brake band,

a second lever secured on the axle, and lugs on the bracket plate withwhich the opposite arm are engageable. v

- HERMAN A. MENNE.

